1. Field of the Invention
The present invention relates to a cash drawer, particularly to a cash drawer which is closed by a simple pushing movement and opened by turning a lock head or by an inward pushing movement, with an elastic force driving a drawer outward without any need for electric power, so that dependence on electric power supply of conventional cash drawers is avoided.
2. Description of Related Art
As shown in FIGS. 11 and 12, a conventional cash drawer comprises a casing 10; a drawer 20; a shift plate 30; a bottom plate 38; a locking device 40; a spring 47; and an opening device 50. The casing 10 has left and right sides carrying rails 11 and rolls 12. The drawer 20 has left and right sides outside of which rails 21 and rolls 22 are mounted which glide on the casing 10. The drawer 20 has a front side on which a lock head 24 is mounted performing opening and closing movements. A connecting rod 26 leads from the lock head 24 rearward and passes through a rear wall of the drawer 20. The shift plate 30 is an elongated plate mounted on the rear wall of the drawer 20 and having a right end and a left end. The right end of the shift plate 30 accommodates a rear end of the connecting rod 26 to glide therein. A middle section of the shift plate 30 has positioning grooves 34 guiding the shift plate 30 to glide over positioning pins 36 and preventing the shift plate 30 from being displaced. The left end of the shift plate 30 is perpendicularly bent, forming an pushing end 37, and is movable to the left and right. The bottom plate 38 is fastened to a lower side of the casing 10 close to a rear side thereof and at a middle position carries a holding knob 39. The locking device 40, as shown in FIG. 4, has an axis 41 mounted on the drawer 20 in front of the rear wall thereof, a catch plate 43, which in a middle part thereof is set on the axis 41, a hook 44, leaning against the pushing end 37 of the shift plate 30, and a catch opening 45 that in a locked state of the drawer 20 engages with the holding knob 39. A spring 47 has an end connected with the catch plate 43 on the axis 41 and another end connected with the rear wall of the drawer 20. The opening device 50 comprises a holding case 52, mounted on the bottom plate 38, an opening spring 54, fastened to the holding case 52 at a front side thereof, and a magnet 60, mounted on the bottom plate 38. The magnet 60 has a push bar 61 to which a push rod 63 is fastened. When electric current passes through the magnet 60, the push bar 61 thereof is longitudinally moved, taking the push rod 63 away from the catch plate 43, so that an opening movement of the catch plate 43 is performed. Closing the drawer 20 causes the catch plate 43 to engage with the holding knob 39 and to be held there in the locked state. For opening the drawer 20, the lock head 24 is manually or by electronic control turned into an open position, causing the connecting rod 26 to shift the shift plate 30 and to operate the magnet 60, so that the push rod 63 and the shift plate 30 move away from the catch plate 43, so that the catch opening 45 thereof becomes disengaged from the holding knob 39 on the bottom plate 38 and the opening spring 54 pushes the drawer 20 outward.
Conventional cash drawers like those just described have a simple structure and are widely used, but have the following disadvantages. (1) Operation is dependent on supply of electricity, and (2) power consumption for repeated opening and closing of the drawer is high.